EP2187177A1 - Plaque réfléchissante pour codeur optique, son procédé de production et que codeur optique optical encoder - Google Patents

Plaque réfléchissante pour codeur optique, son procédé de production et que codeur optique optical encoder Download PDF

Info

Publication number
EP2187177A1
EP2187177A1 EP08829312A EP08829312A EP2187177A1 EP 2187177 A1 EP2187177 A1 EP 2187177A1 EP 08829312 A EP08829312 A EP 08829312A EP 08829312 A EP08829312 A EP 08829312A EP 2187177 A1 EP2187177 A1 EP 2187177A1
Authority
EP
European Patent Office
Prior art keywords
film
reflection plate
optical encoder
reflecting surface
electrolytic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP08829312A
Other languages
German (de)
English (en)
Other versions
EP2187177A4 (fr
Inventor
Satoru Oshida
Masaru Kato
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nikon Corp
Original Assignee
Nikon Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nikon Corp filed Critical Nikon Corp
Publication of EP2187177A1 publication Critical patent/EP2187177A1/fr
Publication of EP2187177A4 publication Critical patent/EP2187177A4/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
    • G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
    • G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
    • G01D5/347—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells using displacement encoding scales
    • G01D5/34707—Scales; Discs, e.g. fixation, fabrication, compensation
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
    • C23C18/54—Contact plating, i.e. electroless electrochemical plating
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C25D11/04—Anodisation of aluminium or alloys based thereon
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C25D11/04—Anodisation of aluminium or alloys based thereon
    • C25D11/18—After-treatment, e.g. pore-sealing
    • C25D11/24—Chemical after-treatment

Definitions

  • the present invention relates to a reflection plate for an optical encoder and a manufacturing method thereof, and an optical encoder having the reflection plate.
  • Priority is claimed on Japanese Patent Application No. 2007-229887, filed on September 5, 2007 , and Japanese Patent Application No. 2007-339778, filed on December 28, 2007 , the contents of which are incorporated herein by reference.
  • An optical encoder is a position sensor for measuring the rotation angles or the movement distances of a subject.
  • Known optical encoders include transmission-type encoders in which light that has passed through the slits provided in the encoder disc is detected by a light receiving element to perform positioning, and reflection-type encoders in which reflection regions and non-reflection regions are provided on the encoder disc, and light that have been reflected from the reflection regions are detected by a light receiving element to perform positioning.
  • Japanese Patent Application Publication No. 2007-121142 discloses a reflection-type encoder disc (a reflection plate for an optical encoder) including: an optical disc; an absorption layer formed on a surface of the optical disc; and a reflection layer patterned on a surface of the absorption layer.
  • a conventional reflection plate for an optical encoder in which a patterned reflection layer is arranged on the surface of a non-reflection layer is manufactured by the following method. That is, as shown in FIGS. 13A to 13F , a non-reflection layer 25 is first formed on a base material 21 by vacuum evaporation, sputtering, or the like ( FIG. 13A ).
  • a reflection layer 26 is formed by vacuum evaporation, sputtering, or the like ( FIG. 13B ).
  • the photoresist film 22 is subjected to exposure via a photomask.
  • the photoresist film 22 after exposure is subjected to development to form a resist pattern 22a ( FIG. 13D ).
  • the reflection layer 26 is subjected to etching or the like to expose the non-reflection layer 25 ( FIG. 13E ).
  • the resist pattern 22a is removed to expose the patterned reflection layer 26 ( FIG. 13F ).
  • a conventional reflection plate for an optical encoder whose surface has non-reflection regions and patterned reflection regions is obtained.
  • each layer is typically deposited by a vacuum process such as vacuum evaporation, sputtering, or the like.
  • vacuum evaporation apparatuses are comparatively expensive, and require a comparatively high equipment cost.
  • exfoliation is produced due to a stain or a scratch on the surface of the layer.
  • aspects according to the present invention have an object to provide a reflection plate for an optical encoder excellent in adhesion, and another object to provide a manufacturing method of a reflection plate for an optical encoder that is low in cost and high in productivity.
  • a reflection plate for an optical encoder including: a base material with a reflecting surface; and a film that is formed on a part of the reflecting surface and includes a non-electrolytic plating film or an electrolytic oxide film.
  • a reflection plate for an optical encoder that is excellent in adhesion is provided.
  • a manufacturing method of a reflection plate for an optical encoder including: preparing a base material with a reflecting surface; and forming a film on a part of the reflecting surface, the film including a non-electrolytic plating film or an electrolytic oxide film.
  • a manufacturing method of a reflection plate for an optical encoder that is low in cost and high in productivity is provided.
  • an optical encoder includes the reflection plate for an optical encoder as set forth in the first aspect.
  • an optical encoder that is low in cost and excellent in durability is provided.
  • a reflection plate 10 for an optical encoder includes: a base material 1 with a specular reflecting surface; and non-electrolytic plating films 3 formed on some parts of the reflecting surface.
  • the non-electrolytic plating films 3 form non-reflection regions (low reflection regions, light-absorbing regions).
  • the parts of the reflecting surface where the non-electrolytic plating films are not formed form reflection regions 15.
  • the reflection region 15 is capable of reflecting light that is absorbed by the non-reflection region (the non-electrolytic plating film 3).
  • the non-electrolytic plating film 3 as a non-reflection region has a reflectance lower than that of the reflection region 15.
  • the non-electrolytic plating films 3 may include a plurality of elements with the same shape and/or a plurality of elements whose shapes are different from each other.
  • the pattern for position detection includes the non-electrolytic plating films 3 as non-reflection regions and the reflection regions 15.
  • the minimum line width or minimum pitch of the pattern is set according to the resolution of the optical encoder, and can be set to, for example, 100, 90, 80, 70, 60, 50, 40, 30, 20, or not more than 10 ⁇ m, or alternatively to not less than 100 ⁇ m.
  • a reflection plate having a pattern with a minimum line width or minimum pitch of not more than approximately 20 ⁇ m can be applicable to an optical encoder with a high resolution.
  • a reflection plate having a minimum line width or minimum pitch of not more than approximately 10 ⁇ m or 5 ⁇ m can be applicable to an optical encoder with a higher resolution.
  • the minimum line width or minimum pitch of the pattern can be set to, for example, approximately 20, 18, 16, 14, 12, 10, 8, 6, 4, or not more than 2 ⁇ m.
  • the non-electrolytic plating films 3 formed on some parts of the reflecting surface of the base material 1 function as non-reflection regions.
  • a non-electrolytic plating process utilizes a difference in standard redox potential (ionization tendency). In displacement plating reactions, electrons are exchanged between a substance with a high ionization tendency and a substance with a low ionization tendency.
  • the constituent substances of the non-electrolytic plating film 3 have direct bonding with the reflecting surface, and the adhesion of the non-electrolytic plating film 3 with the reflecting surface (the specular surface) of the base material 1 is very strong.
  • non-electrolytic plating process is advantageous for avoiding use of a vacuum process when forming the reflection regions and the non-reflection regions, and/or for reducing the cost. Furthermore, use of a non-electrolytic plating process is advantageous for forming a high-resolution pattern (high-definition pattern), securing a predetermined film thickness, and/or obtaining uniformity in film thickness, and is preferably applicable to a reflection plate having a pattern applicable to a high-resolution optical encoder.
  • At least the reflection region 15 can be covered with protection film(s) (coating film(s)) 4 and/or 12a, as shown in FIG. 2, FIG. 3A, and FIG. 3B .
  • protection film(s) coating film(s) 4 and/or 12a
  • the whole surface of the base material 1 including the reflection regions 15 and the non-reflection regions (the non-electrolytic plating films 3) is covered with the protection film 4.
  • the reflection regions 15 are each covered with a protection film 12a.
  • FIG. 3B only the reflection regions 14 are each covered with a first protection film 12a and the whole surface of the base material 1 including the reflection regions 15 and the non-reflection regions (the non-electrolytic plating films 3) is covered with a second protection film 4.
  • a formation material for the protection films 4, 12a with a capability of transmitting light a variety of known materials can be used.
  • the photoresist used for the patterning of the non-electrolytic plating film 3 can be used as the protection films 12a.
  • a transparent photoresist used in the manufacturing method (described later) is allowed to remain on the reflection regions 15 to protect the reflection regions 15.
  • the whole surface of the base material 1 including the aforementioned remaining transparent resist pattern (the protection films 12a) and the non-reflection regions (the non-electrolytic plating films 3) can be further covered with the protection film 4.
  • transparent means transparent to the light that is used for the optical encoder.
  • the reflection plate 10 can be arranged instead of the conventional reflection plate equipped in a typical optical encoder, and hence is adoptable to various types of encoders such as a rotary encoder and a linear encoder.
  • a manufacturing method may be used that includes at least: (A1) a photoresist film formation step; (A2) a resist pattern formation step; and (A5) a non-electrolytic plating step, and further includes, as required: (A3) a caustic neutralization process step; (A4) a metal displacement film formation step; (A6) resist pattern removal step; and (A7) protection film formation step, the steps being as follows.
  • a base material 1 with a specular reflecting surface is prepared, and a photoresist film 2 is formed on the reflecting surface ( FIG. 4A ).
  • the base material 1 is not particularly limited so long as it is a base material having a specular reflecting surface and allows for formation of a non-electrolytic plating film on its reflecting surface by the non-electrolytic plating process.
  • a base material made of an aluminum or an aluminum alloy is preferable because it is possible to form a preferable reflection plate.
  • the base material 1 one in which a metal layer made of an aluminum alloy or the like is formed on the surface of a host material such as a glass substrate or a transparent resin substrate can be used.
  • the metal layer preferably has a thickness of approximately 0.2, 0.5, 1, 2, 3, 4, or not less than 5 ⁇ m, and more preferably has a thickness of not less than 1 ⁇ m. With a thickness of less than 1 ⁇ m, it tends to be difficult to obtain a metal layer with sufficient reflectance.
  • the specular reflecting surface of the base material 1 can be formed by performing mirror machining (mirror-like finishing).
  • mirror machining conventionally known mirror machining methods such as polishing and grinding can be used.
  • polishing and grinding are conventionally known methods because it can form a desired reflecting surface at a low cost.
  • the reflectance of the reflecting surface is preferably, for example, approximately 40, 50, 60, 70, 80, or not less than 90%, and more preferably not less than 70%. If the reflectance of the reflecting surface is less than 70%, it tends to be difficult to obtain a reflection plate with high accuracy. Furthermore, the thickness, size, and shape of the base material 1 can be appropriately determined according to desired applications. Note that "reflectance" mean reflectance with respect to the light used for the optical encoder.
  • a photoresist film 2 is formed on the reflecting surface of the base material 1 by a conventionally known method.
  • a coating apparatus such as a spinner is used to spread a photoresist uniformly on the reflecting surface to form the photoresist film 2.
  • the photoresist may be either positive type or negative type so long as it does not deteriorate through the respective processes (described later).
  • a transparent photoresist is used as the photoresist to form a transparent photoresist film 12 ( FIG. 5A ).
  • the transparent photoresist is required not to deteriorate through the respective processes (described later) and in the environment of use of the reflection plate.
  • one of negative type is used.
  • one of positive type may be used so long as it does not deteriorate.
  • the formed photoresist film 2 or the transparent photoresist film 12 is subjected to a heating process (pre-bake) under predetermined conditions.
  • pre-bake a heating process
  • the pre-bake conditions can be appropriately set according to the type of photoresist that is used and the like.
  • a photomask with a desired encoder pattern formed thereon is adherently or adjacently placed on or above the photoresist film 2 or the transparent photoresist film 12.
  • a light source such as a mercury lamp is used to irradiate energy rays at a predetermined wavelength onto the photoresist film 2 or the transparent photoresist film 12 from above the photomask, to thereby expose the photoresist film 2 or the transparent photoresist film 12 for a predetermined period of time.
  • the exposure conditions can be appropriately set according to the type of the photoresist that is used and the like.
  • the photomask is not particularly limited.
  • Usable photomasks include, for example, one in which an encoder pattern is formed on a glass substrate (preferably, a silica glass substrate) by use of chrome or the like.
  • the photomask After exposure, the photomask is removed, and a predetermined developer (developing solution) is used to perform a development.
  • developer developer solution
  • the type of developer and the development conditions can be determined according to the type of photoresist that is used and the like.
  • the non-exposed parts remain on the base material 1 to form the resist pattern 2a or the transparent resist pattern 12a, and the exposed parts are eluted to expose some parts of the specular surface of the base material 1.
  • the exposed parts remain on the base material 1 to form the resist pattern 2a or the transparent resist pattern 12a, and the non-exposed parts are eluted to expose some parts of the reflecting surface of the base material 1.
  • a reflection plate material FIG. 4B or FIG. 5B
  • the resist pattern may be subjected to a heating process (post-bake) under predetermined conditions.
  • the post-bake conditions can be appropriately set according to the type of photoresist that is used and the like.
  • the reflection plate material obtained in the step (A2) can be subjected, as required, to a caustic process by immersing the reflection plate material in a caustic solution. Through the caustic process, stains on the exposed parts of the reflecting surface are removed.
  • the type of caustic solution can be appropriately determined according to the type of base material that is used and the like. For example, in the case where a base material whose surface is made of an aluminum or an aluminum alloy is used as the base material 1, it is preferable that, as a caustic solution, a sodium hydroxide solution (more preferably, one with a concentration of 10 to 15 percent by mass) be used.
  • the conditions for the caustic process (for example, the immersion temperature and the immersion time) can be appropriately set according to the types of base material and caustic solution that are used and the like.
  • the reflection plate material that has been subjected to the caustic process is immersed in a neutralizing solution to neutralize the exposed parts.
  • the type of neutralizing solution can be appropriately determined according to the type of base material that is used, the type of caustic solution that is used, and the like.
  • a base material at least the surface of which is made of an aluminum or an aluminum alloy is subjected to a caustic process by a sodium hydroxide solution with a concentration of 10 to 15 percent by mass
  • a neutralizing solution a nitric acid aqueous solution with a concentration of 2 to 8 percent by mass (for example, one in which nitric acid with a concentration of 67.5 percent by mass is diluted by pure water) be used.
  • the conditions for the neutralization process for example, the immersion temperature and the immersion time
  • the reflection plate material obtained in the step (A2) or the step (A3) can be immersed, as required, in an alkaline solution (hereinafter, referred to as "solution for metal displacement film formation") contains metallic ions in which an ionization tendency of the metal is weaker than that of the metal forming the reflecting surface of the base material 1 and also is stronger than that of the metal forming the non-electrolytic plating film 3.
  • solution for metal displacement film formation contains metallic ions in which an ionization tendency of the metal is weaker than that of the metal forming the reflecting surface of the base material 1 and also is stronger than that of the metal forming the non-electrolytic plating film 3.
  • the metal of the exposed part of the reflecting surface is displaced with the metal in the solution for metal displacement film formation, to thereby form, on the exposed part, a metal displacement film 5 that includes the metal with an ionization tendency weaker than that of the metal forming the reflecting surface and also stronger than that of the metal forming the non-electrolytic plating film 3 ( FIG. 4C or FIG. 5C ).
  • a metal displacement film 5 By forming a metal displacement film 5 on the exposed part, the metal in the metal displacement film is displaced with the plated metal in the non-electrolytic plating process (described later). This makes it possible to form non-electrolytic plating films with more adhesion to the reflecting surface of the base material 1.
  • the solution for metal displacement film formation can be appropriately determined according to the type of base material that is used, the type of non-electrolytic plating film that is formed, and the like.
  • a base material at least the surface of which is made of an aluminum or an aluminum alloy is used as the base material 1 and non-electrolytic nickel-plating films or non-electrolytic-copper plating films are formed as the non-electrolytic plating films 3
  • an alkaline solution including zinc ions be used as the solution for metal displacement film formation.
  • the non-electrolytic plating process described later, the displacement between the zinc and the nickel or the copper is facilitated. Therefore, it is possible to form non-electrolytic nickel-plating films or non-electrolytic copper-plating films on the surface of the aluminum or the aluminum alloy with ease.
  • the formation conditions of the metal displacement films can be appropriately set according to the types of base material and solution for metal displacement film formation that are used and the like.
  • the thickness of the metal displacement film to be formed is not particularly limited. So long as only the metal on the surface of the exposed part is displaced, it is possible to form a non-electrolytic plating film with a high adhesion to the reflecting surface of the base material 1. Therefore, in this case, the metal displacement film may be thin.
  • the reflection plate material having the metal displacement films that are formed in this manner may be directly subjected to a non-electrolytic plating process.
  • the metal displacement films be exfoliated from the reflection plate material and that new metal displacement films be formed. It is more preferable that the exfoliation and the formation of metal displacement films be repeated.
  • An exfoliation process of the metal displacement films can be performed by immersing the reflection plate material in an acid. As a result, the metal in the metal displacement films are dissolved, and the parts of the reflecting surface of the base material 1 is exposed again.
  • the acid used for the exfoliation of the metal displacement films can be appropriately determined according to the types of base material and metal displacement film that are used and the like. For example, if a base material at least the surface of which is made of an aluminum or an aluminum alloy is used as the base material 1 to form zinc displacement films, it is preferable that a nitric acid aqueous solution (more preferably, a nitric acid aqueous solution with a concentration of 2 to 8 percent by mass) be used as the acid.
  • the exfoliation conditions of the metal displacement film for example, the immersion temperature and the immersion time
  • metal displacement films are again formed on the exposed parts of the reflecting surface by a method similar to the above step of (A4-1).
  • the solution for metal displacement film formation that is used and the formation conditions of the metal displacement films may be the same as or different from those in the above step of (A4-1).
  • the thickness of the metal displacement film to be formed may be thin similarly to the above step of (A4-1).
  • the solution for metal displacement film formation and the acid, and the exfoliation conditions and formation conditions of metal displacement films that are used therefor may be the same as or different from those in the above step of (A4-1) and the above step of (A4-2).
  • the reflection plate material obtained in the step (A2) or the reflection plate material having the metal displacement films that is obtained in the step (A4) is immersed in a non-electrolytic plating solution to form a non-electrolytic plating film on the exposed parts of the reflecting surface.
  • the reflection plate material in which some parts of the reflecting surface of the base material 1 are exposed (the one obtained in the step (A2)) is immersed in the non-electrolytic plating solution, the metal to be plated is precipitated on the exposed parts to form non-electrolytic plating films 3.
  • the reflection plate material having the metal displacement film (the one obtained in the step (A4)) is immersed in the non-electrolytic plating solution, the metal in the metal displacement films is displaced with the plating metal to form non-electrolytic plating films on the parts of the reflecting surface which are not covered with the resist pattern ( FIG. 4D or FIG. 5D ).
  • non-electrolytic plating solution a known non-electrolytic plating solution can be used so long as it includes a metal whose ionization tendency is lower than that of the metal which forms the reflecting surface of the base material 1 (in the case where metal displacement films are provided, a metal whose ionization tendency is lower than that of the metal which forms the metal displacement films) and also so long as it is capable of forming non-electrolytic plating films 3 whose reflectance is lower than that of the reflecting surface of the base material 1.
  • a non-electrolytic nickel plating solution for example, a non-electrolytic black nickel plating solution, a non-electrolytic copper plating solution, or the like may be used as the non-electrolytic plating solution.
  • the conditions of the non-electrolytic plating process (for example, the immersion temperature and the immersion time) can be appropriately set according to the types of base material and non-electrolytic plating solution that are used, the type of formed metal displacement film, and the like.
  • the non-electrolytic plating film 3 formed in this manner has a thickness of, for example, approximately 0.2, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, or not less than 20 ⁇ m, and more preferably approximately 1 to 3 ⁇ m. If the thickness of the non-electrolytic plating film 3 is less than the aforementioned lower limit, the reflectance of the part tends not to lower sufficiently. On the other hand, if the thickness is more than the aforementioned upper limit, the manufacturing time tends to be longer, resulting in a higher cost.
  • the reflectance of the non-electrolytic plating film 3 is preferably, for example, approximately 90, 80, 70, 60, 50, 40, 30, 20, or not more than 10%, and more preferably not more than 50%, of the part on the base material 1 where the non-electrolytic plating film 3 is not formed. If the percentage of the reflectance is more than 50%, the difference in reflectance between the reflection region and the non-reflection region becomes smaller, and the function as a reflection plate for an optical encoder will be lost. That is, this tends to make the correct positioning difficult. It is preferable that the reflectance of the non-electrolytic plating film 3 be lower than that of the reflecting surface, for example, approximately 80, 70, 60, 50, 40, 30, 20, 10, or not more than 5%, and more preferably not more than 30%.
  • a film for forming a non-reflection region a coatingless, or grey- or black-colored non-electrolytic nickel plating film, a non-electrolytic nickel alloy plating film, or a non-electrolytic copper plating film be formed. It is more preferable that a non-electrolytic black nickel plating film or a non-electrolytic black nickel alloy plating film be formed. From the viewpoint of adhesion, uniformity, and corrosion-resistance, it is particularly preferable that a black-colored non-electrolytic nickel phosphorus plating film be formed.
  • the resist pattern is typically removed.
  • the transparent resist pattern is not removed.
  • the reflection plate material obtained in the step (A5) that is the reflection plate ( FIG. 5D ) whose surface has: the reflection regions made of the specular part whose surface is coated with the transparent resist pattern 12a; and the non-reflection regions made of the non-electrolytic plating films 3 can be used as a reflection plate for an optical encoder.
  • one in which the whole surface of the reflection plate or the surface of the transparent resist pattern 12a shown in FIG. 5D is coated with a protection film 4 in the protection film formation step (described later) can be used as a reflection plate for an optical encoder.
  • the resist pattern is typically removed in the case where a photoresist other than a transparent photoresist is used as the photoresist. Note that, even in the case of using a transparent photoresist, the resist pattern may be removed.
  • Methods of removing a resist pattern include a method of immersing the reflection plate material ( FIG. 4D ) obtained in the step (A5) in a resist exfoliation-solution.
  • the resist exfoliation solution one can be appropriately selected from among the conventionally known ones according to the type of photoresist that is used.
  • the immersion conditions can be appropriately set according to the type of resist exfoliation solution that is used.
  • the parts of the reflecting surface of the base material 1 in which the non-electrolytic plating films 3 are not formed are exposed.
  • a reflection plate for an optical encoder FIG. 4E ) that has: reflection regions composed of the specular parts; and non-reflection regions composed of the non-electrolytic plating films 3.
  • the whole surface of the reflection plate, only the reflection regions, or the surface of the transparent resist pattern be coated with a protection film.
  • the protection film can be formed by spreading a material for forming an oxidation-resistant film by use of a coating method such as spin coating, or formed by depositing a dielectric material by use of a vacuum process such as vacuum evaporation or sputtering.
  • the reflection plate for an optical encoder obtained by the aforementioned manufacturing method includes: a base material with a specular reflecting surface; and non-electrolytic plating films formed on some parts of the reflecting surface.
  • the non-electrolytic plating films have low reflectance, and hence, function as non-reflection regions.
  • the parts of the reflecting surface that are not covered with the non-electrolytic plating films (the specular parts) have high reflectance, and hence, function as reflection regions.
  • the non-electrolytic plating film has high adhesion to the reflecting surface of the base material. Therefore, exfoliation between the non-electrolytic plating film and the base material is unlikely to occur.
  • the aforementioned manufacturing method does not use a vacuum process when forming the reflection regions and the non-reflection regions. Therefore, it is a method with law cost and high productivity compared with conventional manufacturing methods of reflection plates for an optical encoder. Furthermore, in the present embodiment, the non-reflection regions are formed by the non-electrolytic plating process. This allows for fine patterning.
  • a cellophane tape was stuck onto non-electrolytic black nickel plating films, and was peeled off quickly. An adhesion was assessed by the presence or absence of an exfoliation of the non-electrolytic black nickel plating film from the discoid member.
  • an aluminum-alloy discoid member 24 mm in diameter, 4 mm in thickness, one surface of which was mirror machined, was used.
  • a positive-type photoresist manufactured by Tokyo Ohka Kogyo Co., Ltd.; product name: "TSMR-8800" was uniformly spread by use of a spinner. After spreading, the discoid member was subjected to a heating process at 100°C for 30 minutes, to thereby perform prebake.
  • a photomask in which a pattern of an encoder was formed on a surface of a silica glass by use of chrome was brought into close contact with (adherently placed on) the positive-type photoresist coating film.
  • a mercury lamp was used to irradiate g-line onto this from above the photomask for approximately 20 seconds, to thereby perform an exposure process.
  • the photomask was removed, and the positive-type photoresist coating film was developed by use of a developer (manufactured by Tokyo Ohka Kogyo Co., Ltd.; product name: "NMD-3").
  • a developer manufactured by Tokyo Ohka Kogyo Co., Ltd.; product name: "NMD-3"
  • the non-exposed parts of the positive-type photoresist coating film remain on the discoid member, and the exposed parts were eluted to expose some parts of the reflecting surface of the discoid member.
  • the discoid member with a surface on which the resist pattern was formed in this manner was immersed for 30 seconds in a sodium hydroxide aqueous solution with a concentration of 12.5 percent by mass maintained at 55°C, to thereby perform a caustic process. As a result, the stain on the exposed parts of the reflecting surface was removed.
  • the discoid member was immersed for 10 seconds in a nitric acid aqueous solution with a concentration of 5 percent by mass (one in which a nitric acid with a concentration of 67.5 percent by mass was diluted by pure water) maintained at room temperature. As a result, the surface of the discoid member having been subjected to the caustic process was neutralized.
  • the discoid member was immersed for one minute in a zinc displacement solution (manufactured by Kizai Corporation; product name: "SZ-II") maintained at room temperature.
  • a zinc displacement solution manufactured by Kizai Corporation; product name: "SZ-II”
  • the aluminum in the exposed parts of the reflecting surface was displaced with zinc to form zinc films on the exposed parts.
  • the discoid member having the zinc films was immersed for 10 seconds in a nitric acid aqueous solution with a concentration of 5 percent by mass (one in which a nitric acid with a concentration of 67.5 percent by mass was diluted by pure water) maintained at room temperature.
  • a nitric acid aqueous solution with a concentration of 5 percent by mass one in which a nitric acid with a concentration of 67.5 percent by mass was diluted by pure water
  • the zinc films were removed from the discoid member, thus exposing again the parts of the reflecting surface of the discoid member that were not covered with the photoresist film.
  • the discoid member was immersed for one minute in a zinc displacement solution (manufactured by Kizai Corporation; product name: "SZ-II”) maintained at room temperature.
  • a zinc displacement solution manufactured by Kizai Corporation; product name: "SZ-II”
  • the aluminum in the exposed parts of the reflecting surface was displaced with zinc, forming zinc films on the exposed parts again.
  • the discoid member having the zinc films was immersed for 10 minutes in a non-electrolytic nickel plating solution (manufactured by Japan Kanigen Co., Ltd.; product name: "KANIBLACK SKZ)) maintained at 90°C.
  • a non-electrolytic nickel plating solution manufactured by Japan Kanigen Co., Ltd.; product name: "KANIBLACK SKZ) maintained at 90°C.
  • the zinc on the exposed parts was displaced with black nickel, forming non-electrolytic black nickel plating films with a thickness of approximately 2 ⁇ m on the exposed parts.
  • the resist pattern on the surface of the discoid member was removed by use of a resist exfoliation solution, thus exposing the protected rest parts (the specular parts) of the reflecting surface of the discoid member.
  • a reflection plate for an optical encoder whose surface has: reflection regions made of specular parts of the aluminum-alloy discoid member; and non-reflection regions made of non-electrolytic black nickel plating films was obtained.
  • discoid member was appropriately rinsed with pure water after each process.
  • a transparent negative-type photoresist manufactured by MicroChem Corporation; product name "SU-8 3050" was uniformly spread by use of a spinner. After spreading, the discoid member was subjected to a heating process at 95°C for 30 minutes, to thereby perform pre-bake.
  • the discoid member with a surface on which the transparent negative-type photoresist was formed was subjected to an exposure process similar to Example 1. After that, the discoid member was subjected to a development process similar to Example 1, the exception being that SU-8 Developer (product name) manufactured by MicroChem Corporation was used as the developer. Subsequently, the discoid member was subjected to a heating process at 95°C for 30 minutes, to thereby perform post-bake.
  • Non-electrolytic black nickel plating films with a thickness of approximately 2 ⁇ m were formed on the exposed parts of the reflecting surface of the discoid member similar to Example 1, the exception being that a discoid member with a surface on which a transparent resist pattern was formed was used.
  • a reflection plate for an optical encoder whose surface has: reflection regions which are made of the specular parts of the aluminum-alloy discoid member and which are covered with the transparent negative-type photoresist; and non-reflection regions made of the non-electrolytic black nickel plating films was obtained.
  • FIG. 6 is a cross-sectional view showing a reflection plate for an optical encoder according to another embodiment.
  • a reflection plate 11 for an optical encoder includes: a base material 1 with a specular reflecting surface; and electrolytic oxide films 6 formed on some parts of the reflecting surface.
  • the electrolytic oxide films 6 form non-reflection regions (low reflection regions, light-absorbing regions).
  • the parts of the reflecting surface that are not electrolytically oxidized (the specular parts) form reflection regions 15.
  • the reflection region 15 is capable of reflecting light that is absorbed by the non-reflection region (the electrolytic oxide film 6).
  • the electrolytic oxide film 6 as a non-reflection region has a reflectance lower than that of the reflection region 15.
  • the electrolytic oxide films 6 may include a plurality of elements with the same shape and/or a plurality of elements whose shapes are different from each other.
  • the pattern for position detection includes: the electrolytic oxide film 6 as non-reflection regions; and the reflection regions 15.
  • the minimum line width or minimum pitch of the pattern is set according to the resolution of the optical encoder, and can be set to, for example, 100, 90, 80, 70, 60, 50, 40, 30, 20, or not more than 10 ⁇ m, or alternatively to not less than 100 ⁇ m.
  • a reflection plate having a pattern with a minimum line width or minimum pitch of not more than approximately 20 ⁇ m can be applicable to an optical encoder with a high resolution.
  • a reflection plate having a minimum line width or minimum pitch of not more than approximately 10 ⁇ m can be applicable to an optical encoder with a higher resolution.
  • the minimum line width or minimum pitch of the pattern can be set to, for example, approximately 20, 18, 16, 14, 12, 10, 8, 6, 4, or not more than 2 ⁇ m.
  • the electrolytic oxide films 6 formed on some parts of the reflecting surface of the base material 1 function as non-reflection regions.
  • the constituent substances of the electrolytic oxide film 6 has direct bonding with the reflecting surface, and the adhesion of the electrolytic oxide film 6 with the reflecting surface (the specular surface) of the base material 1 is very high.
  • Use of an electrolytic oxidation process is advantageous for avoiding use of a vacuum process when forming the reflection regions and the non-reflection regions, and/or for reducing the cost.
  • an electrolytic oxidation process is advantageous for forming a high-resolution pattern, securing a predetermined film thickness, and/or obtaining uniformity in film thickness, and is preferably applicable to a reflection plate having a pattern applicable to a high-resolution optical encoder.
  • At least the reflection region 15 can be covered with protection film(s) (coating film(s)) 4 and/or 12a, as shown in FIG. 7, FIG. 8A, and FIG. 8B .
  • protection film(s) coating film(s) 4 and/or 12a
  • the whole surface of the base material 1 including the reflection regions 15 and the non-reflection regions (the electrolytic oxide films 6) is covered with the protection film 4.
  • FIG. 8A only the reflection regions 15 are each covered with a protection film 12a.
  • FIG. 8B only the reflection regions 14 are each covered with a first protection film 12a and the whole surface of the base material 1 including the reflection regions 15 and the non-reflection regions (the electrolytic oxide films 6) is covered with a second protection film 4.
  • a material for the protection films 4 and 12a a variety of known materials can be used.
  • the photoresist used for the patterning of the electrolytic oxide film 6 can be used as the protection films 12a.
  • the transparent photoresist used in the manufacturing method (described later) is allowed to remain on the reflection regions 15 to protect the reflection regions 15.
  • the whole surface of the base material 1 including the aforementioned remaining transparent resist pattern (the protection films 12a) and the non-reflection regions (the electrolytic oxide films 6) can be further covered with the protection film 4.
  • transparent means transparent to the light that is used for the optical encoder.
  • a manufacturing method includes at least: (B1) a photoresist film formation step, (B2) a resist pattern formation step, and (B3) an electrolytic oxidation step, and further includes, as required: (B4) a dyeing step, (B5) a resist pattern removal step, and (B6) a protection film formation step, the steps being as follows.
  • a base material 1 with a specular reflecting surface is prepared, and a photoresist film 2 is formed on the reflecting surface ( FIG. 9A ).
  • the base material 1 is not particularly limited so long as it is a base material having a specular reflecting surface and allows for formation of a surface with a lower reflectance than that of the reflecting surface by electrolytic oxidation.
  • a base material made of an aluminum or an aluminum alloy is preferable because it is possible to form a preferable reflection plate.
  • the base material 1 one in which a metal layer made of an aluminum alloy or the like is formed on the surface of a host material such as a glass substrate or a transparent resin substrate can be used.
  • the metal layer preferably has a thickness of approximately 2, 4, 6, 8, 10, 15, or not less than 20 ⁇ m, and more preferably has a thickness of not less than 10 ⁇ m. With a thickness of less than 10 ⁇ m, it tends to be difficult to form an electrolytic oxide film with a sufficient thickness.
  • the specular reflecting surface of the base material 1 can be formed by mirror machining methods.
  • the mirror machining method conventionally known mirror machining methods such as polishing and grinding can be used. Among these, grinding is preferable because it can form a desired reflecting surface at a low cost.
  • the reflectance of the reflecting surface is preferably, for example, approximately 40, 50, 60, 70, 80, or not less than 90%, and more preferably not less than 70%. If the reflectance of the reflecting surface is less than 70%, a reflection plate with high accuracy tends to be unobtainable. Furthermore, the thickness, size, and shape of the base material 1 are appropriately determined according to desired applications. Note that “reflectance” means reflectance with respect to the light used for the optical encoder.
  • a photoresist film 2 is formed by a conventionally known method.
  • a coating apparatus such as a spinner is used to spread a photoresist uniformly on the reflecting surface to form a photoresist film 2.
  • the photoresist may be either positive type or negative type so long as it does not deteriorate through electrolytic oxidation.
  • a transparent photoresist is used as the photoresist to form a transparent photoresist film 12 ( FIG. 10A ).
  • the transparent photoresist may be either positive type or negative type so long as it does not deteriorate through electrolytic oxidation.
  • the formed photoresist film 2 or the transparent photoresist film 12 is subjected to a heating process (pre-bake) under predetermined conditions.
  • pre-bake a heating process
  • the pre-bake conditions are appropriately set according to the type of photoresist that is used.
  • a photomask with a desired encoder pattern formed thereon is placed in contact with or proximity to the photoresist film 2 or the transparent photoresist film 12.
  • a light source such as a mercury lamp is used to irradiate energy rays at a predetermined wavelength onto the photoresist film 2 or the transparent photoresist film 12 from above the photomask, to thereby expose the photoresist film 2 or the transparent photoresist film 12 for a predetermined period of time.
  • the exposure conditions are appropriately set according to the type of photoresist that is used.
  • the photomask is not particularly limited.
  • Usable photomasks include, for example, one in which an encoder pattern is formed on a glass substrate (preferably, a silica glass substrate) by use of chrome or the like.
  • the photomask After exposure, the photomask is removed, and a predetermined developer is used to perform a development.
  • the type of developer and the development conditions are determined according to the type of photoresist that is used.
  • the non-exposed parts remain on the base material 1 to form the resist pattern 2a or the transparent resist pattern 12a, and the exposed parts are eluted to expose some parts of the specular surface of the base material 1.
  • the exposed parts remain on the base material 1 to form the resist pattern 2a or the transparent resist pattern 12a, and the non-exposed parts are eluted to expose some parts of the reflecting surface of the base material 1.
  • the resist pattern may be subjected to a heating process (post-bake) under predetermined conditions.
  • the post-bake conditions are appropriately set according to the type of photoresist that is used.
  • the reflection plate material obtained in the step (B2) is connected to electrodes, and is immersed in an electrolytically oxidizing solution.
  • the electrolytically oxidizing solution is appropriately determined according to the type of base material 1 that is used. For example, in the case where a base material at least the surface of which is made of an aluminum or an aluminum alloy is used as the base material 1, an anodizing solution (alumite treatment liquid) in which 1 L of pure water is mixed with 180 g of sulfuric acid with a concentration of 75% is used as the electrolytically oxidizing solution.
  • the exposed parts of the reflecting surface are electro-oxidized, to thereby form electrolytic oxide films 6 whose surfaces have a myriad of fine pores formed ( FIG. 9C or FIG. 10C ).
  • the type of electrolytic oxide film 6 depends on the type of base material 1 that is used. If the base material 1 is made of aluminum, the electrolytic oxide film 6 is aluminum oxide film. If the base material 1 is made of aluminum alloy, the electrolytic oxide film 6 is aluminum alloy oxide film.
  • the electrolytic oxide film 6 has a typical thickness of approximately 2, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 ⁇ m, preferably approximately 10 to 70 ⁇ m, and more preferably approximately 15 to 50 ⁇ m. If the thickness of the electrolytic oxide film 6 is less than 15 ⁇ m, the reflectance of this part tends not to lower sufficiently. On the other hand, with a thickness over 50 ⁇ m, the manufacturing time tends to be longer, resulting in a higher cost.
  • typically a part thereof is formed so as to be raised above the level of the reflecting surface of the base material 1, and the remaining part is formed below the level of the reflecting surface of the base material 1.
  • the thickness of the raised part is typically approximately 1/3 to 1/2 of the whole thickness of the electrolytic oxide film 6.
  • the reflectance of the electrolytic oxide film 6 that is formed in this manner is preferably, for example, approximately 90, 80, 70, 60, 50, 40, 30, 20, or not more than 10%, and more preferably not more than 50%, of the reflectance of the reflecting surface of the base material 1. If the percentage of the reflectance of the electrolytic oxide film 6 with respect to that of the reflecting surface of the base material 1 is more than 50%, the difference in reflectance between the reflection region and the non-reflection region tends to be small, correct positioning tends to be difficult.
  • the reflectance of the electrolytic oxide film 6 is preferably lower than that of the reflecting surface. It is, for example, preferably approximately 80, 70, 60, 50, 40, 30, 20, 10, or not more than 5%, and more preferably not more than 30%.
  • the resist pattern is typically removed.
  • the transparent resist pattern is not removed.
  • the reflection plate material obtained in the step (B3) that is the reflection plate material ( FIG. 10C ) whose surface has: the reflection regions made of the specular part whose surface is coated with the transparent resist pattern 12a; and the non-reflection regions made of the electrolytic oxide films 6, can be used as a reflection plate 11 for an optical encoder.
  • the electrolytic oxide films 6 (the non-reflection regions) be dyed. This decreases the reflectance of the electrolytic oxide film 6. It is preferable that, to prevent the reflection regions from being dyed, the dyeing process be performed before the resist pattern is removed.
  • Dyeing methods include one in which the reflection plate material that is obtained in the electrolytic oxidation step is immersed in a dye solution to impregnate the electrolytic oxide films 6 with the dye. Furthermore, because the impregnated dye has gone into the pores (holes) of the electrolytic oxide films 6, the dye can be sealed in the pores by sealing the entrances of the pores, to thereby prevent decoloration at the time of a rinsing process or the like. This sealing can be performed by immersing the reflection plate material after the dyeing process in a sealing solution.
  • the dye solution a black dye solution in which a black dye is dissolved into pure water, and a dye solution with a deep color like black can be used.
  • the black dye solution is preferable in that it is capable of further reducing the reflectance of the non-reflection regions.
  • the sealing solution one in which a chemical based on nickel acetate, cobalt acetate, or the like is dissolved in water can be used.
  • the resist pattern is typically removed in the case where a photoresist other than a transparent photoresist is used as the photoresist. Note that, even in the case of using a transparent photoresist, the resist pattern may be removed.
  • Methods of removing a resist pattern include a method of immersing the reflection plate material obtained in the electrolytic oxidation step or the dyeing step in a resist remover.
  • the resist remover one can be appropriately selected from among the conventionally known ones and used according to the type of photoresist that is used. Furthermore, the immersion conditions are appropriately set according to the type of resist remover that is used.
  • the parts of the reflecting surface of the base material 1 which are not electrolytically oxidized are exposed.
  • a reflection plate FIG. 9D ) that has: reflection regions made of the specular parts; and non-reflection regions made of the electrolytic oxide films 6.
  • the whole surface of the reflection plate, only the reflection regions, or the surface of the transparent resist pattern be coated with a protection film.
  • the protection film can be formed by spreading a material for forming an oxidation-resistant film by use of a coating method such as spin coating, or formed by depositing a dielectric material by use of a vacuum process such as vacuum evaporation or sputtering.
  • a coating method such as spin coating
  • a vacuum process such as vacuum evaporation or sputtering
  • the reflection plate for an optical encoder obtained by the aforementioned manufacturing method electrolytically oxidizes the base material surface directly. This prevents the exfoliation between the formed electrolytic oxide films and the base material. Furthermore, the aforementioned manufacturing method does not use a vacuum process when forming the reflection regions and the non-reflection regions. Therefore, it is a method low in cost and high in productivity compared with conventional manufacturing methods of reflection plates for an optical encoder.
  • a cellophane tape was stuck onto electrolytic oxide films, and was peeled off quickly. The presence or absence of an exfoliation of the electrolytic oxide films from the discoid member was checked.
  • an aluminum-alloy discoid member 24 mm in diameter, 4 mm in thickness, one surface of which was mirror machined, was used.
  • a positive-type photoresist manufactured by Tokyo Ohka Kogyo Co., Ltd.; product name: "TSMR-8800" was uniformly spread by use of a spinner. After spreading, the discoid member was subjected to a heating process at 100°C for 30 minutes, to thereby perform prebake.
  • a photomask in which a pattern of an encoder was formed on a surface of a silica glass by use of chrome was brought into close contact with (adherently placed on) the positive-type photoresist coating film.
  • a mercury lamp was used to irradiate the g-line onto this from above the photomask for approximately 20 seconds, to thereby perform an exposure process.
  • the photomask was removed, and the positive-type photoresist coating film was developed by use of a developer (manufactured by Tokyo Ohka Kogyo Co., Ltd.; product name: "NMD-3").
  • a developer manufactured by Tokyo Ohka Kogyo Co., Ltd.; product name: "NMD-3"
  • the non-exposed parts of the positive-type photoresist coating film remain on the discoid member, and the exposed parts were eluted to expose some parts of the reflecting surface of the discoid member.
  • An electrode was connected to the discoid member with the resist pattern formed on its surface in this manner.
  • This discoid member was immersed in an anodizing solution (one in which 1 L of pure water is mixed with 180 g of sulfuric acid with a concentration of 75%) maintained at 20°C, and current with a current density of 2 A/dm 2 was applied thereto for 40 minutes.
  • anodizing solution one in which 1 L of pure water is mixed with 180 g of sulfuric acid with a concentration of 75% maintained at 20°C, and current with a current density of 2 A/dm 2 was applied thereto for 40 minutes.
  • the aluminum alloy on the exposed parts of the reflecting surface was anodized, and aluminum alloy oxide films were formed on some parts of the surface of the discoid member.
  • This aluminum alloy oxide films had a thickness of approximately 24 ⁇ m.
  • the part formed above the level of the reflecting surface of the discoid member had a thickness of approximately 8 ⁇ m, and the part of it formed below the level of the reflecting surface had a thickness of approximately 16 ⁇ m. Furthermore, when the aluminum alloy oxide films were observed under a microscope, it was confirmed that a myriad of fine pores (holes) were formed in their surfaces.
  • the discoid member having the aluminum alloy oxide film on some parts of its reflecting surface was immersed for 15 minutes in a black dye solution (one in which 10 g of a black dye (manufactured by Okuno Chemical Industries Co., Ltd., product name: "TAC-413”) was dissolved in 1 L of pure water) maintained at 60°C. This allowed the dye to go into the pores of the aluminum alloy oxide films, thus dyeing the aluminum alloy oxide film black.
  • a black dye solution one in which 10 g of a black dye (manufactured by Okuno Chemical Industries Co., Ltd., product name: "TAC-413"
  • the discoid member in which the aluminum alloy oxide films were dyed black in this manner was immersed for 15 minutes in a sealing solution (one in which 2 ml of Lyogen WL Liq (product name; manufactured by Clariant) was dissolved in 1 L of pure water) maintained at 95°C to close the entrances of the pores of the aluminum alloy oxide films. Thus, the black dye was sealed in the pores. After that, the discoid member was immersed and rinsed for approximately 3 seconds in pure water maintained at 70°C.
  • a sealing solution one in which 2 ml of Lyogen WL Liq (product name; manufactured by Clariant) was dissolved in 1 L of pure water
  • the resist pattern on the surface of the discoid member was removed by use of an exfoliation solution to expose the protected remaining parts (the specular parts) on the reflecting surface of the discoid member.
  • a reflection plate for an optical encoder including: reflection regions made of the specular parts of the aluminum-alloy discoid member; and non-reflection regions made of the black-dyed aluminum alloy oxide films was obtained.
  • a transparent positive-type photoresist manufactured by MicroChem Corporation; product name "SU-8 50" was uniformly spread by use of a spinner. After spreading, the discoid member was subjected to a heating process at 65°C for 6 minutes, and subsequently at 95°C for 20 minutes, to thereby perform pre-bake
  • the discoid member with a surface on which the transparent positive-type photoresist was formed was subjected to an exposure process similarly to Example 3. After that, the discoid member was subjected to a development process similar to Example 3, the exception being that SU-8 Developer (product name) manufactured by MicroChem Corporation was used as a developer. Subsequently, the discoid member was subjected to a heating process at 65°C for 2 minutes, and subsequently at 95°C for 5 minutes, to thereby perform post-bake.
  • Electrodes were connected to the discoid member with the transparent resist pattern formed on its surface in this manner. Then, aluminum alloy oxide films were formed on some parts of the surface of the discoid member similar to Example 3.
  • the aluminum alloy oxide films had a thickness of approximately 24 ⁇ m.
  • the part formed above the level of the reflecting surface of the discoid member had a thickness of approximately 8 ⁇ m, and the part of it formed below the level of the reflecting surface had a thickness of approximately 16 ⁇ m.
  • the aluminum alloy oxide films were observed under a microscope, it was confirmed that a myriad of fine pores were formed in their surfaces.
  • the aluminum alloy oxide film was dyed black, had the black dye sealed, and rinsed with pure water in a manner similar to the case of Example 3.
  • a reflection plate for an optical encoder whose surface includes: a reflection region that is made of the specular part of the aluminum-alloy discoid member and is covered with the transparent positive-type photoresist; and a non-reflection region made of the black-dyed aluminum alloy oxide film was obtained.
  • the reflection plates (Example 3 and 4) were free from the occurrence of exfoliation, and hence, were excellent in adhesion. Furthermore, in the aforementioned manufacturing method, a vacuum process was not used when the reflection regions and the non-reflection regions were formed. Therefore, it was a method low in cost and high in productivity.
  • the reflection plates 10, 11 are applicable to various types of encoders such as a rotary encoder and a linear encoder. Furthermore, as an encoder pattern in each of the reflection plates 10, 11, various patterns such as an incremental pattern and an absolute pattern can be used.
  • FIG. 11 is a plan view schematically showing one example of an encoder.
  • FIG. 12 is a side view showing a rough construction of the encoder of FIG. 11 .
  • an encoder 100 is a multi-turn absolute rotary encoder. It includes: a scale plate (a reflection plate) 101; detection portions 102, 103, 104; and a rotary shaft 105.
  • the scale plate 101 and the detection portions 102 to 104 move relative to each other.
  • the rotary shaft 105 is rotatable.
  • the scale plate 101 is attached to the rotary shaft 105.
  • the scale plate 101 On the scale plate 101, there are provided a first track 106 for an absolute pattern, a second track 107 for an incremental pattern, and a third track 108 for counting the number of rotations.
  • the scale plate 101 has a substantially discoid (disc-like) or annular shape.
  • the first track 106, the second track 107, and the third track 108 have an annular shape, and are arranged concentrically.
  • the first track 106 is arranged in an outermost circumference of the scale plate 101, and has a 1-track-type absolute pattern arranged along the circumferential direction.
  • the second track 107 is arranged inner than the first track 106, and has an incremental pattern arranged along the circumferential direction.
  • the third track 108 is arranged inner than the second track 107, and has a magnetic S-N pattern.
  • Each pattern of the first and second tracks 106, 107 is an optical pattern.
  • the third track 108 is made of, for example, a magnet disc.
  • the detection portion 102 includes: magnetic sensors 120A, 120B that are placed so as to face the third track 108 of the scale plate 101; and a signal processing portion (not shown in the figures) for processing signals from the magnetic sensors 120A, 120B.
  • the detection portion 102 is capable of outputting biphase signals (for examples, signals out of phase from each other by 90°) in accordance with the number of rotations of the third track 108.
  • the detection portions 103, 104 each include: a light-receiving element for receiving light reflected from the scale plate 101, the light being from a light projector (not shown in the figures); and a signal processing portion for processing signals from the light-receiving element.
  • detection light dispersed light from an LED or the like is used for example.
  • detection light converted into substantially parallel rays via a predetermined optical element enters the scale plate 101.
  • Reflected rays from the scale plate 101 enter the light-receiving elements of the detection portions 103, 104.
  • the detection portion 103 is capable of detecting reflected rays from the absolute pattern of the first track 106.
  • the detection portion 104 is capable of detecting reflected rays from the incremental pattern of the second track 107.
  • the encoder 100 it is possible to measure the relative rotational position (rotation angle) of the scale plate 101 with high accuracy based on the signals from the detection portions 102 to 104.
  • the scale plate 101 either of the reflection plates 10, 11 according to the aforementioned embodiments can be used.
  • the encoder 100 can be low in cost and have excellent durability.
  • a detailed construction of a multi-turn absolute rotary encoder is disclosed in, for example, Japanese Patent Application Publication Nos. H09-273943 , H09-089591 , H09-061195 , and 2005-121593 .
  • the reflection plate for an optical encoder of the present invention is useful as, for example, a reflection plate for an optical encoder that is used in a severe environment and/or a reflection plate for an optical encoder that requires a high resolution. Furthermore, the manufacturing method of a reflection plate for an optical encoder of the present invention is low in equipment cost, and hence, is useful for reducing the cost of the reflection plate for an optical encoder.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Electrochemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • General Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Optical Transform (AREA)
  • Optical Elements Other Than Lenses (AREA)
EP08829312A 2007-09-05 2008-09-04 Plaque réfléchissante pour codeur optique, son procédé de production et que codeur optique optical encoder Withdrawn EP2187177A4 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2007229887 2007-09-05
JP2007339778 2007-12-28
PCT/JP2008/065958 WO2009031608A1 (fr) 2007-09-05 2008-09-04 Plaque réfléchissante pour codeur optique, son procédé de production et que codeur optique optical encoder

Publications (2)

Publication Number Publication Date
EP2187177A1 true EP2187177A1 (fr) 2010-05-19
EP2187177A4 EP2187177A4 (fr) 2012-12-26

Family

ID=40428921

Family Applications (1)

Application Number Title Priority Date Filing Date
EP08829312A Withdrawn EP2187177A4 (fr) 2007-09-05 2008-09-04 Plaque réfléchissante pour codeur optique, son procédé de production et que codeur optique optical encoder

Country Status (6)

Country Link
US (2) US8368004B2 (fr)
EP (1) EP2187177A4 (fr)
JP (1) JP5240198B2 (fr)
CN (2) CN101836089B (fr)
TW (1) TWI454665B (fr)
WO (1) WO2009031608A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2597431A1 (fr) * 2011-11-22 2013-05-29 Mitutoyo Corporation Échelle de codeur photoélectrique et son procédé de fabrication
CN104018203A (zh) * 2014-06-06 2014-09-03 广东南桂起重机械有限公司 一种铝型材氧化专用行车定位检测装置及专用行车

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2468263B (en) * 2008-08-28 2013-04-03 Faro Tech Inc Indexed optical encoder method for indexing an optical encoder, and method for dynamically adjusting gain and offset in an optical encoder
US8829421B2 (en) * 2011-02-21 2014-09-09 Mitsubishi Electric Corporation Optical encoder
JP5850710B2 (ja) 2011-11-07 2016-02-03 キヤノン株式会社 エンコーダ用反射型光学式スケール及び反射型光学式エンコーダ
WO2013100061A1 (fr) 2011-12-28 2013-07-04 株式会社ニコン Codeur, procédé de production pour échelle de codeur, procédé de production pour codeur et dispositif de commande
US20130221212A1 (en) * 2012-02-24 2013-08-29 Avago Technologies Ecbu Ip (Singapore) Pte. Ltd. Coding Members With Embedded Metal Layers For Encoders
JP6197480B2 (ja) * 2013-08-23 2017-09-20 オムロン株式会社 光学式エンコーダ用遮光板、その製造方法およびそれを用いた光学式エンコーダ
US10317254B2 (en) * 2014-03-27 2019-06-11 Ams Sensors Singapore Pte. Ltd. Optical encoder system
US10119842B1 (en) * 2014-08-05 2018-11-06 X Development Llc Encoder design and use
JP5925365B1 (ja) * 2015-05-13 2016-05-25 株式会社メルテック 光学式エンコーダ用格子板および光学式エンコーダ用格子板の製造方法
CN106929897A (zh) * 2015-12-30 2017-07-07 比亚迪股份有限公司 一种铝合金壳体及其制备方法
TWI585647B (zh) * 2016-04-07 2017-06-01 奇象光學有限公司 光學膜片以及使用者輸入系統
TWI597637B (zh) * 2016-08-12 2017-09-01 奇象光學有限公司 光學膜片以及使用者輸入系統
JP6958237B2 (ja) * 2017-10-30 2021-11-02 セイコーエプソン株式会社 エンコーダースケール、エンコーダースケールの製造方法、エンコーダー、ロボット、電子部品搬送装置、プリンターおよびプロジェクター
JP7140495B2 (ja) 2017-12-28 2022-09-21 株式会社ミツトヨ スケールおよびその製造方法
JP6628266B1 (ja) * 2018-10-17 2020-01-08 株式会社プロセス・ラボ・ミクロン 光学式エンコーダ用反射板とその製造方法
CN112444277A (zh) 2019-09-04 2021-03-05 台达电子工业股份有限公司 光学反射部件及其适用的光学编码器
CN113753846A (zh) * 2021-09-07 2021-12-07 上海晶采微纳米应用技术有限公司 高精度金属光码盘制备方法及高精度金属光码盘

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6145923A (ja) * 1984-08-10 1986-03-06 Aronshiya:Kk 反射式ロ−タリ−エンコ−ダ−用回転デイスクの製作方法
US4644156A (en) * 1984-01-18 1987-02-17 Alps Electric Co., Ltd. Code wheel for reflective optical rotary encoders
US4661697A (en) * 1984-04-13 1987-04-28 Alps Electric Co., Ltd. Optically reflecting code plate
JPS62153710A (ja) * 1985-12-27 1987-07-08 Furukawa Alum Co Ltd ロ−タリエンコ−ダ用反射基板の製造方法
JP2004045063A (ja) * 2002-07-09 2004-02-12 Topcon Corp 光学式ロータリーエンコーダ板の製造方法および光学式ロータリーエンコーダ板
US6814897B2 (en) * 1998-03-27 2004-11-09 Discovision Associates Method for manufacturing a molding tool used for substrate molding
JP2007119851A (ja) * 2005-10-27 2007-05-17 Nippon Kanizen Kk 黒色めっき膜およびその形成方法、めっき膜を有する物品

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR920003400B1 (ko) * 1983-12-29 1992-04-30 가부시기가이샤 히다찌세이사꾸쇼 금속과 수지와의 복합체 및 그 제조방법
JPS61267005A (ja) * 1985-05-21 1986-11-26 Mitsubishi Electric Corp 色分解フイルタ及びその製造方法
JPS63177617A (ja) * 1987-01-19 1988-07-21 Derufuai:Kk 反射型ロ−タリエンコ−ダの回転板の製造方法
US4961077A (en) * 1988-02-19 1990-10-02 E. I. Du Pont De Nemours And Company Method for affixing information on read-only optical discs
KR0119377B1 (ko) * 1993-12-10 1997-09-30 김주용 반도체장치 제조방법
JPH0961195A (ja) 1995-08-30 1997-03-07 Nikon Corp ロータリエンコーダ及びその組み立て装置
JPH0989591A (ja) 1995-09-22 1997-04-04 Nikon Corp 多回転アブソリュートエンコーダ
JPH09273943A (ja) 1996-04-05 1997-10-21 Nikon Corp 多回転アブソリュート・エンコーダ
KR100407413B1 (ko) * 1999-07-19 2003-11-28 마쯔시다덴기산교 가부시키가이샤 반사판 및 그 제조방법, 및 반사판을 구비한 반사형표시소자 및 그 제조방법
US7316837B2 (en) * 2000-07-21 2008-01-08 Target Technology Company, Llc Metal alloys for the reflective or the semi-reflective layer of an optical storage medium
JP2004151076A (ja) * 2002-09-04 2004-05-27 Kenseidou Kagaku Kogyo Kk ハブ一体型反射型光学式エンコーダー用回転部品
JP4433759B2 (ja) 2003-10-20 2010-03-17 株式会社ニコン アブソリュートエンコーダ
US20060127821A1 (en) * 2004-12-09 2006-06-15 Sanyo Electric Co., Ltd. Method of forming a photoresist pattern
CN101180557B (zh) * 2005-03-29 2013-03-13 京瓷株式会社 发光装置以及照明装置
JP2007119581A (ja) 2005-10-27 2007-05-17 Unitika Ltd ポリアミド樹脂組成物および成形品
JP4877573B2 (ja) 2005-10-28 2012-02-15 株式会社ニコン エンコーダディスクおよびエンコーダ
CN1790068A (zh) * 2005-12-23 2006-06-21 中国科学院光电技术研究所 多层膜反射式高精度金属圆光栅及其制作方法
JP5308059B2 (ja) * 2008-04-25 2013-10-09 株式会社ミツトヨ 光電式エンコーダ用スケール

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4644156A (en) * 1984-01-18 1987-02-17 Alps Electric Co., Ltd. Code wheel for reflective optical rotary encoders
US4661697A (en) * 1984-04-13 1987-04-28 Alps Electric Co., Ltd. Optically reflecting code plate
JPS6145923A (ja) * 1984-08-10 1986-03-06 Aronshiya:Kk 反射式ロ−タリ−エンコ−ダ−用回転デイスクの製作方法
JPS62153710A (ja) * 1985-12-27 1987-07-08 Furukawa Alum Co Ltd ロ−タリエンコ−ダ用反射基板の製造方法
US6814897B2 (en) * 1998-03-27 2004-11-09 Discovision Associates Method for manufacturing a molding tool used for substrate molding
JP2004045063A (ja) * 2002-07-09 2004-02-12 Topcon Corp 光学式ロータリーエンコーダ板の製造方法および光学式ロータリーエンコーダ板
JP2007119851A (ja) * 2005-10-27 2007-05-17 Nippon Kanizen Kk 黒色めっき膜およびその形成方法、めっき膜を有する物品

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO2009031608A1 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2597431A1 (fr) * 2011-11-22 2013-05-29 Mitutoyo Corporation Échelle de codeur photoélectrique et son procédé de fabrication
US9258007B2 (en) 2011-11-22 2016-02-09 Mitutoyo Corporation Scale of photoelectric encoder including base member having roughened surface and manufacturing method of scale
CN104018203A (zh) * 2014-06-06 2014-09-03 广东南桂起重机械有限公司 一种铝型材氧化专用行车定位检测装置及专用行车
CN104018203B (zh) * 2014-06-06 2016-06-01 广东南桂起重机械有限公司 一种铝型材氧化专用行车定位检测装置及专用行车

Also Published As

Publication number Publication date
TWI454665B (zh) 2014-10-01
EP2187177A4 (fr) 2012-12-26
US8368004B2 (en) 2013-02-05
WO2009031608A1 (fr) 2009-03-12
TW200912261A (en) 2009-03-16
JPWO2009031608A1 (ja) 2010-12-16
CN101836089B (zh) 2013-06-05
US20100193671A1 (en) 2010-08-05
US20130070359A1 (en) 2013-03-21
CN102980602B (zh) 2016-07-06
JP5240198B2 (ja) 2013-07-17
CN101836089A (zh) 2010-09-15
CN102980602A (zh) 2013-03-20

Similar Documents

Publication Publication Date Title
US8368004B2 (en) Reflection plate for optical encoder and manufacturing method thereof, and optical encoder
EP1816518B1 (fr) Moule pour impression et processus de production de structure fine utilisant le moule
KR101223368B1 (ko) 전자 회로 장치와 그 제조 방법
CN104094087A (zh) 编码器、编码器用标尺制造方法、编码器制造方法及驱动装置
US5478699A (en) Method for preparing a screen printing stencil
US4661697A (en) Optically reflecting code plate
US3370948A (en) Method for selective etching of alkali glass
EP0049799B1 (fr) Photoréserve vierge et photomasque
US3922206A (en) Method of photo-etching and photogravure using fission fragment and/or alpha ray etch tracks from toned photographs
CA1269342A (fr) Methode d'electroformage d'article, avec un mandrin a photomasque
JP2012063200A (ja) 光学式エンコーダ用反射板、エンコーダ及び光学式エンコーダ用反射板の製造方法
JP3571396B2 (ja) カラーフィルタおよびカラーフィルタの製造方法
KR100994160B1 (ko) 토크 및 비틀림 각 검출 센서용 옵티컬 디스크 제조 방법
KR940006038B1 (ko) 금속부분증착물의 제조방법
US4565616A (en) Method for producing a photoelectroforming mandrel
JPH02140655A (ja) 電気化学的検出器およびその製造方法
US20220057353A1 (en) Light-activated gas sensor based on 3d nanostructure operable at low temperature with high performance and method for manufacturing the same
KR20190053427A (ko) 필름 마스크 및 그 제조 방법
JP3191383B2 (ja) 印刷版の製造方法
CN101268530A (zh) 电子零件及其制造方法
CN1230334A (zh) 合成材料表面的构造方法、尤其是用于数据存储的数据载体的制造方法
JPH0781882B2 (ja) ロータリーエンコーダ用ディスク及びその製造方法
JP2003268573A (ja) 精密金属部品の製造方法
JPS5812337B2 (ja) ビサイパタ−ンノ トウメイマクノケイセイホウホウホウ
JPH10126039A (ja) プリント配線基板などのエッチング方法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20100308

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA MK RS

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: NIKON CORPORATION

DAX Request for extension of the european patent (deleted)
A4 Supplementary search report drawn up and despatched

Effective date: 20121122

RIC1 Information provided on ipc code assigned before grant

Ipc: C23C 18/54 20060101ALI20121116BHEP

Ipc: C25D 11/04 20060101ALI20121116BHEP

Ipc: G01D 5/30 20060101AFI20121116BHEP

Ipc: C25D 11/02 20060101ALI20121116BHEP

Ipc: G01D 5/347 20060101ALI20121116BHEP

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: NIKON CORPORATION

17Q First examination report despatched

Effective date: 20171005

RIC1 Information provided on ipc code assigned before grant

Ipc: C25D 11/24 20060101ALI20180220BHEP

Ipc: C25D 11/04 20060101ALI20180220BHEP

Ipc: G01D 5/30 20060101AFI20180220BHEP

Ipc: C23C 18/54 20060101ALI20180220BHEP

Ipc: C25D 11/02 20060101ALI20180220BHEP

Ipc: G01D 5/347 20060101ALI20180220BHEP

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

INTG Intention to grant announced

Effective date: 20180406

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20180817